Patient controlled analgesia (PCA) is emerging as a very promising technique of administrating pain medication (narcotics). By using an electronic delivery system complete with a timer and syringe pump, a patient can intravenously deliver on demand (through an intravenous line) a present amount of pain medication. Presently, most post-operative pain medication is deliverd intramuscularly and it is felt that there are some deficiencies with this method. In this study we will allow adult post cardiac surgery patients to control their own post-operative analgesia. Upon discharge from the ICU, the patient will be allowed to use the delivery system for a 72 hour period. Morphine will be the narcotic used. The designated incremental dose of morphine will be 1.0 mg, which can be administered every 8 minutes at a maximum. The patients will strive for analgesia, but minimal sedation. The incremental dose is subject to change depending upon the patient's response. The safety of PCA has been demonstrated in the treatment of post-operative pain. The specific machines used are FDA-approved.